So you have a CV 740 Kohler.
You will find your full repair manual on the Kohler web site, log in as a guest.
Or you can get a PDF of it from here
https://www.mymowerparts.com/pdf/Kohler-Service-and-Repair-Manuals/
Yours is the one that starts with CV25.
There are 2 likely sources of your problem
1) one of the ignition modules is failing
2) air leak on one cylinder
Easy one for starters, pull the blower housing and remove the spark plugs one at a time then start the engine ( plugs must be grounded )
If the engine runs smooth with one disconnected and will not run at all with the other disconnected then one of the ignition modules is shot.
next start the engine, and manually apply the choke a very little bit, gradually increasing till you start to get 8 stroking and some black smoke.
If it ran better with a small amount of choke then you have an air leak